Feral druid / holy paladin is serious easy mode. Moreso than dk/pally imo from a boxers point of view.

I do 2v2 with r/l friend of mine and we decided i needed a rogue for a rogue/mage team. I hit 80 and we broke 1800 that night with my rogue in blues/AH epics. I don't think rogues are all that complicated but dual boxing them might be seriously insane multi tasking.

We shelved the the rogue again for my feral druid not too long later. The burst is beyond ridiculous, my record crit was 16.5k vs a mage and we almost lost the match cause I was laughing too hard to finish his teammate.

I would say dual boxing 2's arena u have no choice but stealth or insane burst. (2x rogue / feral / maybe mage) or a healer plate or healer / feral combo.